Conventionally, a wide variety of light-transmitting dielectric sheets are manufactured by factories. For example, anisotropy of any plastic sheet normally emerges itself by elongation applied during molding process to cause the film tensile strength to eventually vary according to the rate of elongation applied, or the anisotropy emerges from the thermal deformation during heating process due to varied thermal expansion coefficient caused by directional factors. Consequently, in order to securely stabilize dimension, orientation of plastic molecules making up a film should strictly be controlled. Conventionally, molecular orientation of plastic film is checked by either X-ray diffraction pattern, infrared dichroism, or by measurement of the aspect ratio of the dynamic strength. However, any of these conventional methods needs a considerable time for correctly determining the orientation characteristic. Furthermore, it is difficult for any of these conventional systems to quickly detect whether the aimed orientation is securely achieved during film molding process, or not, before advising manufacturing staff of the checked result to allow them to correctly control the orientation. As a result, all the concerned keenly look forward to an early implementation of a novel system capable of easily and quickly checking and confirming the orientation of dielectric sheets.